How to merge layers without change the image?
Hello, I have a question, there's a way to merge layers (CTRL + E) without change the image?

I need to put all layers in one and flat the image, leaving only the background and the very fist photo not merged.
I placed in the background a photo and with other layers I did some modification (adding lights and smudge the image) in separated layers, one for example for hair , one for other details etc..)
After I finish adding lights and things I wanted to add over the original photo, I wanted to unite all the layers :

I selected all 3 layers and merge them with CTRL +E
But, it come out always in this way:

I would like the merge all layers, there's a way to have one single image, without this effect?
Thanks in advance for the help!
